1. Field of the Invention
The present invention relates to an insert clamping wedge (hereinafter, referred to as a clamp wedge) which is used to detachably clamp-fix a cutting insert to an insert attachment seat of a cutter body in an insert-detachable type cutter such as a face mill and also relates to an insert-detachable type cutter which is mounted with the clamp wedge so as to attach the cutting insert thereto.
Priority is claimed on Japanese Patent Application No. 2008-88334, filed Mar. 28, 2008, the content of which is incorporated herein by reference.
2. Description of Related Art
An insert-detachable type cutter using a clamp wedge is disclosed in, for example, Japanese Examined Patent Application Publication, Second Publication No. H01-44443, Japanese Unexamined Patent Application, First Publication No. H01-295709, and PCT International Publication No. WO 2008/023361. The insert-detachable type cutter includes a cutter body, a cutting insert, and a clamp wedge which is used to fix the cutting insert to the cutter body. The cutter body is provided with an insert attachment seat and a recessed portion which communicates with the insert attachment seat. The cutting insert is seated in the insert attachment seat. The clamp wedge is inserted into the recessed portion. The clamp wedge is pressed by a pressing member such as a clamp screw so as to be inserted into the cutter body along a wedge surface of the clamp wedge. At this time, the cutting insert having a polygonal flat plate shape seated in the insert attachment seat is pressed into the insert attachment seat in a thickness direction so as to be clamp-fixed thereto by means of a clamp surface of the clamp wedge. Here, the surface of the clamp wedge is inclined so that the distance between the wedge surface and the surface of the clamp wedge becomes smaller in a press-insertion direction.
In order to reliably fix the cutting insert by means of the clamp wedge, it is necessary to ensure a large area of the clamp surface. However, in the clamp wedge disclosed in Japanese Examined Patent Application Publication, Second Publication No. H01-44443, Japanese Unexamined Patent Application, First Publication No. H01-295709, and PCT International Publication No. WO 2008/023361, a section perpendicular to the press-insertion direction is fumed such that the clamp surface is fanned in a square shape and the wedge surface is formed in a semicircular arc shape which has the same width as that of the square shape and is smoothly connected to the square shape. That is, the clamp wedge is formed in a semicircular arc shape (barrel roof shape or vault shape). Accordingly, when the width of the clamp surface in the section increases in order to increase the area of the clamp surface, the radius of the semicircular arc shape of the wedge surface increases. That is, when the area of the clamp surface increases, the wedge body simply increases in size.
When the wedge body increases in size, the recessed portion of the cutter body mounted with the clamp wedge increases in size. On the other hand, the distance between the recessed portion and the outer peripheral surface of the cutter body becomes smaller. Accordingly, when the clamp wedge is pressed so as to clamp the insert, the clamping strength may deteriorate or the thinned portion may be deformed or damaged.
Recently, in such an insert-detachable type cutter, a so-called increase in the number of blades is required so as to realize the high efficiency of processing by increasing the number of blades provided in the cutter body. Accordingly, the number of the cutting inserts and the clamp wedges for fixing the same tends to increase. However, in the case where the number of cutting blades increases, the gap between the insert attachment seat and the recessed portion is limited. As a result, it is difficult to form the recessed portion having a large area described above.